Brain in Wernicke's disease. Section through a brain affected by Wernicke's disease. Wernicke's disease, or Wernicke's encephalopathy, is a condition that causes lesions of the central nervous system as a result of vitamin B insufficiency, in particular thiamine. It causes neurological symptoms characterised by ophthalmoplegia (weakness of the eye muscles), ataxia (loss of voluntary muscle coordination) and confusion. Here, it has been caused by alcohol abuse. Treatment is with thiamine injections.